Electric scissors

ABSTRACT

An electric scissors having a rotary motor for oscillating a pivotal cutting blade to effect a cutting engagement along a small portion thereof with a ledger blade. The ledger blade, which is normally non-movable during the cutting operation, is mounted such that it may be selectively pivoted into engagement with the cutting blade to effect a snip cutting stroke along substantially the entire cutting blade or a portion thereof. Two embodiments are shown for effecting the snip cut. A first embodiment biases the ledger blade in a normally fixed position by a torsion spring which may be compressed to effect a snip by pushing the ledger blade against a table-like surface. The other embodiment disclose a lever arrangement whereby the ledger blade is pivoted to effect a snip by manually squeezing a lever-link against the force of a spring.

O 1 Unite States Patent 1151 3,676,928

Herr et al. [451 July 18, 1972 [54] ELECTRIC SCISSQRS [72] Inventors:John A. Herr, Gardwood; Oswald M. Pmimry Condo" P n t b th fN JAS81810!!! Exammer-J. C. Peters 0 vmgs o Attorney-Marshall J. Breen,Chester A. Williams, Jr. and [73] Assignee: The Singer Company, NewYork, NY. Alan Rudefman [22] Filed: July 1, 1970 57 ABSTRACT [21] APPLNOJ 51,466 An electric scissors having a rotary motor for oscillating apivotal cutting blade to effect a cutting engagement along a 52 us. c1..30/22s Small Ponion there with a ledge blade- The ledBe' blade 51 Int.Cl. ..B26b 15/00 which is mmany during the Cutting 58 Field ofSear-ch..30/201 202 203 228 233 ismwmedsuchthatitmay selectively Pivmdintoengage" 6 ment with the cutting blade to effect a snip cutting strokealong substantially the entire cutting blade or a portion 56 R f Cithereof. Two embodiments are shown for efiecting the snip 1 e erencested cut. A first embodiment biases the ledger blade in a normally UNITEDSTATES PATENTS fixed position by a torsion spring which may becompressed to effect a snip by pushing the ledger blade against atable-like 1,587,718 6/1926 Gent le ..3o/247 Surfacg The other mbodimentdisclose a lever mangemem 1,656,626 1/1928 Ghana whereby the ledgerblade is pivoted to effect a snip by 1,818,900 8/1931 MacNamee" manuallysqueezing a lever-link against the force of a spring. 2,709,300 5/1955Bl0mberg..... 2,799,928 7/1957 Mays 8 Claims, 3 Drawing figures Paten ted July 18, 1972 VIIIIIIII/Ifl/IflIl/IIiI/IIIIIIIIIIIIIIIIII 4INVENTORS. John A. Herr Oswald M. Porter BY W%RNEY WITNESS BFM ELECTRICSCISSORS BACKGROUND OF THE INVENTION This invention relates to powerdriven scissors or shears, and more particularly to a hand held fabriccutting electric scissors adapted for both rapid power cutting andmanually controlled snipping.

Portable electric scissors of the prior art have a major disadvantage inthat there is a general lack of control when cutting sharp angles andsmall contours. This was recognized in copending US. Patent applicationSer. No. 51,467 filed on July 1, 1970 by John A. I-Ierr and assigned tothe present assignee. That application discloses an electric scissorshaving a controlled snip capability whereby the operator may selectivelyeffect a full and controlled snip along substantially the entire cuttingsurface of the blade. Disclosed in the said co-pending application is avibratory motor for normally oscillating the cutting blade. However,inasmuch as vibratory motors have an inherent tendency for the amplitudeof vibration to decrease as the load increases the cutting efficiency ofan electric scissors with this type power unit is greatly reducedbecause of less work output per stroke as the amplitude decreases. Onthe other hand, a rotary type motor may be applied in an electricscissors as a means for obtaining a constant amplitude oscillation ofthe cutting blade. However, because of the more complicated drivearrangements required when using a rotary motor to drive the cuttingblade of an electric scissors, this invention is directed toward asimple, low cost and effective snip and cut electric scissors in whichthe ledger blade is selectively moved to effect a controlled snip.

SUMMARY OF THE INVENTION The present invention, therefore, provides anelectric scissors in which the ledger blade is fixedly mounted relativeto the motor driven cutting blade and the scissors housing during normalcutting operations, but may be moved selectively to effect a controlledsnip. In a first embodiment the ledger blade is directly connected to aspring which biases the ledger blade about a pin into a fixed positionduring normal cutting operation. To effect a snip the ledger blade isforced against a tablelike surface as the scissors housing is turnedrelative thereto. In a second embodiment the ledger blade is resilientlybiased about a pin into a fixed position during normal cutting by a pairof lever-links and a spring acting against one of the links. When a snipis desired the operator merely squeezes one of the lever-links tocompress the spring and force the other link to pivot the ledger bladeinto engagement with the motor driven cutting blade.

It is, therefore, a primary object of the present invention to provide apower driven hand held scissors having a ledger blade mounted so as tobe fixed during the normal cutting operations, but which is selectivelymovable to effect a controlled snip.

Another object of this invention is to provide an electric scissorshaving a cutting blade adapted to oscillate into engagement with anonnally fixed ledger blade, and having means for permitting the ledgerblade to be moved into cutting engagement with the cutting blade toeffect a snip.

A further object of this invention is to provide an electric scissorshaving a rotary motor and having the capability of selectively effectinga controlled snip.

A still further object of this invention is to provide an electricallypowered scissors in which the ledger blade may be moved selectively toeffect a cut along substantially the entire cutting surface of thedriven blade.

BRIEF DESCRIPTION OF THE DRAWINGS For a fuller understanding of thenature and objects of the invention reference should be had to thefollowing description taken in connection with the accompanyingdrawings, in which:

FIG. 1 is an elevational view of an electric scissors incorporating afirst embodiment of our invention, with parts of said scissors brokenaway and in cross section, and with the ledger blade illustrated bysolid lines in its normally fixed position and by broken lines in thefull snip position;

FIG. 2 is a perspective view partially broken away of the driveincorporated in the scissors of FIG. 1; and

FIG. 3 is an elevational view of an electric scissors incorporating asecond embodiment of our invention, with parts thereof partially brokenaway and in cross section, and with the ledger blade shown by solidlines in its normally fixed position and with broken lines illustratingthe full snip position.

DESCRIPTION OF THE INVENTION Referring to the drawings wherein likeelements are designated by like numerals, an electric scissorsincorporating a first embodiment of our invention is illustrated in FIG.1 and is generally indicated as 10. The scissors unit includes a housing12 preferably comprising two molded sections secured together by meansof screws (not shown). Mounted within the housing is an electric motor14 preferably of the rotary type having a rotatable output shaft 16.

A cutting blade 18 is pivotably mounted in the housing on a pin or axle20. The blade 18 is driven from the output shaft 16 of the motor 14 byany drive means capable of converting rotary motion to pivotaloscillatory motion. A drive having this capability is generallyindicated as 22 and is clearly illustrated in FIG. 2 as comprising acrank 24 having an eccentrically mounted crank pin 26. Secured to thetail end 28 of the blade 18 is a yoke member 30 having a pair of legs 32and 34 between which is mounted a block member 36 having a slotsubstantially parallel to the pin 20. A pair of pins 40 (only one ofwhich is shown) mount the block 36 between the legs 32 and 34 to allowfor limited pivotal movement of the block. In operation, as the motorshaft 16 rotates the crank pin drives the yoke 30 and blade 18 throughthe block 36 pivotally about the pin 20. The slot 38 effectivelyrestrains the motion of the yoke 30 to a single plane substantiallynormal to the pin 20.

To effect a cut under normal operation, the blade 18 operates against aledger blade 42 by pivotably oscillating into and out of cooperativecutting engagement therewith. The cut, it should be noted, occurs alonga very small portion of the blades, since the oscillation of blade 18 issmall. To maintain the ledger blade fixed during normal cuttingoperation, but to allow the blade to move during the snip operation, theledger blade is pivotably mounted on the pin 20 along with the blade 18.The ledger blade is biased to a normally fixed position about the pin 20in a direction that tends to separate the two blades, i.e.,counterclockwise as viewed in FIG. 1, by a torsion spring 44. A stop 45maybe utilized to prevent further counterclockwise movement of the blade42 during normal cutting so that the spring need not be of excessivesize. The spring 44 is mounted upon a boss 46 which may form a portionof the means for securing the molded housing sections together. One endof the spring 44 is located to abut against a stop member 48 while theother end thereof is bent to securely fit a hole 50 in the blade 42. Thelocation of the hole 50 is such that the torque of the spring creates abending moment on the blade 42 relative to the pin 20 so that the blade42 is biased away from the blade 18, and cannot move unless and untilthe spring 44 is compressed.

When it is desired to effect a snip cut with the scissors disclosed inFIG. 1, the operator merely forces the ledger blade 42 against atable-like surface and rolls the housing 12 relative to that blade tocreate a bending moment on the blade that overcomes that due to thespring. This compresses the spring to the dotted position shown in FIG.1 and the ledger blade may be moved to contact a portion of or theentire blade 18 to effect a snip with the blade 42 up until its tip 52.

The embodiment of FIG. 1, of course, requires a surface against whichthe ledger blade must be forced to effect a snip. It is often desirableto have a scissors of this type in which a snip may be performed withoutthe aid of such a surface. The embodiment of FIG. 3 discloses anelectric scissors 1 10 having this capability. Mounted within a housing112 is a rotary type motor 114 having an output shaft 116. A cuttingblade 118 is pivoted on a pin 120 in the housing and is pivotablyoscillated from the shaft 116 by a crank 124 mounted on the shaft andwhich includes a crank pin 126 which oscillates the blade 118 through ayoke member 130 secured to the tail 128 of the blade 1 18. This drive issimilar to that described in connection with the embodiment of FIG. 1and is detailed in FIG. 2.

The blade 118 operates against a ledger blade 142 to effect a cut alonga small portion of the blade. The ledger blade 142 is pivoted on the pin120 and is biased to a normally fixed position, as shown by the solidlines, by means of a resiliently mounted lever arrangement, presentlydescribed.

Pivotably mounted on a pin 129 in the housing is a link 131 having anopen slot 133 at one end thereof and a pin 135 adjacent the other endthereof. Mounted on the blade 142, at a location relative to the pin 120such that the blade 142 is normally biased away from blade 118, is a pin137. The pin 137 is fitted within the slot 133 to restrain the blade 142against movement independently of the link 131. A second link 141 ispivotably mounted at the rear of the housing by means of a pin 143, andis adapted to engage the pin 135. A leaf spring 144 acts on the link 131to bias the ledger blade 142 away from the oscillatable blade 118 andtoward a stop member 145 similar to that of stop 45.

As can be readily seen from FIG. 3 of the drawings, the spring and leverarrangement is such that the ledger blade is biased counterclockwiseabout pin 120 and remain as shown by the solid lines until the force ofthe spring is overcome. This is the position of the ledger blade duringthe normal cutting operation. When it is desired to effect a snip, theoperator merely squeezes the link lever 141. The pin 135 on link 131thereby causes this link to pivot about pin 129 and compress the spring144. The slot 133 of link 131 thereby applies a force against pin 137 onthe ledger blade to pivot the blade clockwise to effect a snip, as shownby the broken lines in FIG. 3. As in the embodiment of FIG. 1 the snipmay be a full contact between the ledger blade and the cutting blade ormay be a portion thereof which is larger than the contact made betweenthe blades during the normal cutting operation.

Numerous alterations of the structure herein disclosed will suggestthemselves to those skilled in the art. However, it is to be understoodthat the present disclosure relates only to preferred embodiments of myinvention which is for purposes of illustration only and not to beconstrued as a limitation of the invention. All such modifications whichdo not depart from the spirit of the invention are intended to beincluded within the scope of the appended claims.

Having thus disclosed the nature of the invention, what we claim hereinis:

1. An electric scissors, comprising a housing, a motor mounted in saidhousing, a normally fixed ledger blade, mounting means including pivotmeans for pivotably mounting said ledger blade to said housing, a secondblade supported in said housing and adapted to be oscillated by saidmotor,

drive means connecting said motor and said second blade for oscillatingsaid second blade into and out of cooperative cutting engagement withsaid normally fixed ledger blade along a first contact area of saidblades, said mounting means further including resilient means forselectively permitting the normally fixed ledger blade to be pivotedmanually from the normally fixed position toward and into cuttingengagement with said second blade along a second contact area of saidblades to effect a snip, said second area being greater than said firstarea.

2. An electric scissors as recited in claim 1 wherein said resilientmeans comprises a torsion spring having one end thereof secured to saidledger blade at a location with respect to said pivot means such thatwhen said ledger blade is selectively relatively pivoted about saidpivot means into cutting engagement with said second blade to effect asnip said spring is compressed from a normal into an energystoredcondition,

3. An electric scissors as recited in c arm 2 wherein said pivot meansfor supporting said ledger blade also pivotably supports said secondblade for oscillation by said drive means.

4. An electric scissors as recited in claim 3 wherein said motor is arotary motor.

5. An electric scissors, comprising a housing, a motor mounted in saidhousing, a normally fixed ledger blade mounted in said housing, a secondblade supported in said housing and adapted to be oscillated by saidmotor, drive means connecting said motor and said second blade foroscillating said second blade into and out of cooperative cuttingengagement with said normally fixed ledger blade, pivot means forsupporting said ledger blade in said housing, lever means connected tosaid ledger blade and pivotably secured to said housing, and a spring inengagement with said lever means for biasing the same, said lever meansbeing connected to said ledger blade at a location with respect to saidpivot means such that said ledger blade is biased away from said secondblade about said pivot means, said lever means being adapted to bemanually selectively pivoted relative to said housing to overcome thebias of said spring for pivoting said ledger blade into cuttingengagement with said second blade to effect a snip.

6. An electric scissors as recited in claim 5 wherein said pivot meansfor supporting said ledger blade also pivotably supports said secondblade for oscillation by said drive means.

7. An electric scissors as recited in claim 8 wherein said motor is arotary motor.

8. An electric scissors as recited in claim 5 wherein said lever meanscomprises a first link, a pin pivotably mounting said first link in saidhousing, a second link having first and second extremities, said secondlink being pivotably mounted intermediate said extremities in saidhousing, means connecting said first extremity to said first link forpivotally moving said second link relative to said housing upon pivotalmovement of said first link, and means for connecting said secondextremity to said ledger blade.

1. An electric scissors, comprising a housing, a motor mounted in saidhousing, a normally fixed ledger blade, mounting means including pivotmeans for pivotably mounting said ledger blade to said housing, a secondblade supported in said housing and adapted to be oscillated by saidmotor, drive means connecting said motor and said second blade foroscillating said second blade into and out of cooperative cuttingengagement with said normally fixed ledger blade along a first contactarea of said blades, said mounting means further including resilientmeans for selectively permitting the normally fixed ledger blade to bepivoted manually from the normally fixed position toward and intocutting engagement with said second blade along a second contact area ofsaid blades to effect a snip, said second area being greater than saidfirst area.
 2. An electric scissors as recited in claim 1 wherein saidresilient means comprises a torsion spring having one end thereofsecured to said ledger blade at a location with respect to said pivotmeans such that when said ledger blade is selectively relatively pivotedabout said pivot means into cutting engagement with said second blade toeffect a snip said spring is compressed from a normal into an energystored condition.
 3. An electric scissors as recited in claim 2 whereinsaid pivot means for supporting said ledger blade also pivotablysupports said second blade for oscillation by said drive means.
 4. Anelectric scissors as recited in claim 3 wherein said motor is a rotarymotor.
 5. An electric scissors, comprising a housing, a motor mounted insaid housing, a normally fixed ledger blade mounted in said housing, asecond blade supported in said housing and adapted to be oscillated bysaid motor, drive means connecting said motor and said second blade foroscillating said second blade into and out of cooperative cuttingengagement with said normally fixed ledger blade, pivot means forsupporting said ledger blade in said housing, lever means connected tosaid ledger blade and pivotably secured to said housing, and a spring inengagement with said lever means for biasing the same, said lever meansbeing connected to said ledger blade at a location with respect to saidpivot means such that said ledger blade is biased away from said secondblade about said pivot means, said lever means being adapted to bemanually selectively pivoted relative to said housing to overcome thebias of said spring for pivoting said ledger blade into cuttingengagement with said second blade to effect a snip.
 6. An electricscissors as recited in claim 5 wherein said pivot means for supportingsaid ledger blade also pivotably supports said second blade foroscillation by said drive means.
 7. An electric scissors as recited inclaim 8 wherein said motor is a rotary motor.
 8. An electric scissors asrecited in claim 5 wherein said lever means comprises a first link, apin pivotably mounting said first link in said housing, a second linkhaving first and second extremities, said second link being pivotablymounted intermediate said extremities in said housing, means connectingsaid first extremity to said first link for pivotally moving said secondlink relative to said housing upon pivotal movement of said first link,and means for connecting said second extremity to said ledger blade.